Streaming multiple .flv files

I wasn't able to find any useful resources on the net for this particular setup, so it seems to be a pretty unexplored area or I'm just unable to use search engines, so here we go:
I've got multiple .flv files which need to be streamed in sequence, without noticeable gaps between them; the .flv files are going to be created dynamically, so there is no way to join them before the actual streaming takes place.

Now it should be possible to modify an existing flash video player in order to automatically get the next file while the current one is being played, but I'm wondering whether there's a way to having a single big .flv file and just appending additional files after they have been created.

Is it possible to make a streaming server "aware" of the changed file size? Or is HTTP streaming more appropriate in this case?

Any information or advice on the subject would be much appreciated!

Well, I don't really know whether it is a good idea to make FLV files larger. I would use dyamic playlists instead.

Adobe Flash Player progressive download (no streaming is used)
Flash Player 7 introduced a new technique called progressive download, which enables developers to use ActionScript commands to feed external FLV files into a SWF file and play them back at runtime. More specifically, you can use the netConnection and netStream objects in ActionScript to set the FLV file to play back, and to control the Play, Pause, Seek (to a timecode), and Close behaviors and the buffer time and size for a given video file.

In this method, the video content (FLV file) is kept external to the other Flash content and the video playback controls. Because of this, it's relatively easy to add or change content without republishing the SWF file.

Adobe Flash Media Server
ActionScript access is the same as for Progressive FLV. You can also use server-side ActionScript to provide additional functionality such as synchronization of streams, server-side playlists, smart delivery adjusted to client connection speed, and more.

This approach provides programmatic control of streams (server scripting) for the creation of server-side playlists, synchronization of streams, smarter delivery adjusted to client connection speed, and application creation.

You can dynamically pull FLV from virtual locations, such as your SAN or the Flash Video Streaming Service CDN.